Prevention andEarly Detection

Advances in cancer prevention and early detection have resulted in
some of the greatest reductions in cancer mortality, and these have
been achieved with remarkable impact by translating scientific
discoveries into actions by two complementary strategies: public
health initiatives involving education and policy, and personalized
initiatives applied in the clinic. Public health measures have
included public education regarding common cancer risks (such as
physical inactivity and unhealthy diets) and policy development to
minimize harmful exposures (such as smoke-free workplaces or
asbestos remediation laws). Clinical preventive advances include
improved screening practices (e.g., colonoscopy to detect and
remove precancerous colorectal polyps) and targeted interventions
(e.g., administering vaccines for infectious diseases associated
with cancer risk).

This progress has come from decades of research that have led us
to our current understanding of how cancers develop. We know
that cancer is a complex process that takes place over a period of
time, sometimes several decades. Most, if not all, tumors arise as a
result of a series of changes in our genes or in the molecules that
control how and when our genes are expressed. Our knowledge of
the timing, sequence and frequency of the pivotal changes
underlying tumor development is increasing, as is our insight into
the specific implications of these changes. This provides us with
unique opportunities for earlier identification of aberrations and
therefore new prospects for developing the means to prevent
cancer onset or to detect it and intervene earlier in its progression.
We have also learned that cancer risk factors are varied, complex
and interrelated, making it challenging, but not insurmountable, to
deliver on the promise of cancer prevention. The identification of
research priorities along with the necessary funding will help to
accelerate progress in this important area.

25% of all deaths in the U.S.
are caused by cancer.

2/3 of cancer deaths are a result
of preventable causes.

To Know Your Risk,Know the Causes of CancerCauses of Cancer You Can Avoid

Through the identification of numerous factors germane to cancer,
scientists have come to the conclusion that almost two thirds of the
more than 577,000 cancer deaths expected to occur in the U.S. in
2012 will be related to preventable causes [( 3); see Fig. 9, pg. 29].

Tobacco Use and Cancer: Smoking-Gun Evidence

One of the most successful examples of how scientific progress
can inform public policy and educational efforts to measurably
reduce cancer incidence and death rates is the 29% decline in lung
cancer death rates among men that occurred between 1990 and
2008, which is directly attributable to the decrease in smoking
prevalence ( 4). The scientifically established causal relationship
between smoking and cancer, which began with epidemiological
observations, gained prominence in the public arena in 1964 when
the U.S. Surgeon General’s Report on Smoking and Health was
published ( 12). This report set in motion major U.S. policy changes,
media campaigns and other measures to combat cigarette smoking
(see Fig. 10, pg. 30). As a result of these efforts, the prevalence of
smoking in the U.S. decreased from 42% of the population in 1965
to 19% in 2010 ( 13). This decrease has been credited with saving
millions of lives that would otherwise have been lost not only to
lung cancer, but also to 17 other types of cancer directly related to
tobacco use, including head and neck, stomach, pancreas,
cervical and other cancers ( 13), as well as to many other often
fatal diseases.

Despite this progress, tobacco use will still be responsible for anestimated 30% of all cancer deaths that occur in the U.S. in 2012( 3). The Surgeon General’s 31st report on tobacco ( 14), released inAACR Cancer Progress Report 2012